Larry Ellison owner of BMW Oracle Racing team holds up a key to the city presented to him by San Francisco Mayor Gavin Newsom during a ceremony at San Francisco City Hall on Saturday. Ellison and his team won the 33rd America's Cup in Spain earlier this month as representatives of The Golden Gate Yacht Club.

Photo: Lance Iversen, The Chronicle

Larry Ellison owner of BMW Oracle Racing team holds up a key to the...

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BMW Oracle Racing owner Larry Ellison and his wife Melanie Craft talk with San Francisco Mayor Gavin Newsom at the conclusion of a ceremony Saturday Feb. 20, 2010 in which the Mayor welcomed Ellison and his team back to San Francisco after they won the 33rd America's Cup trophy in Spain.
Ran on: 02-21-2010
Above: Mayor Gavin Newsom (left) chats with team leader Larry Ellison and his wife, Melanie Craft, at the event that drew throngs to City Hall, left.
Ran on: 02-21-2010
Photo caption Dummy text goes here. Dummy text goes here. Dummy text goes here. Dummy text goes here. Dummy text goes here. Dummy text goes here. Dummy text goes here. Dummy text goes here.<137,1970-12-18-17-21-52,><252>###Photo: amcup21_ph2<252>1266537600<252>SFC<252>###Live Caption:BMW Oracle Racing owner Larry Ellison and his wife Maloney Craft talk with San Francisco Mayor Gavin Newsom at the conclusion of a ceremony in which the Mayor welcomed Ellison and his team back to San Francisco after they won the 33rd America's Cup trophy in Spain. Saturday Feb. 20, 2010.###Caption History:BMW Oracle Racing owner Larry Ellison and his wife Maloney Craft talk with San Francisco Mayor Gavin Newsom at the conclusion of a ceremony in which the Mayor welcomed Ellison and his team back to San Francisco after they won the 33rd America's Cup trophy in Spain. Saturday Feb. 20, 2010.###Notes:Lance Iversen Phone 415-297-9395_CQ###Special Instructions:**MANDATORY CREDIT FOR PHOTOG AND SF CHRONICLE-NO SALES-MAGS OUT-TV OUT-INTERNET: AP MEMBER NEWSPAPERS ONLY**<137><252>

Billionaire software titan Larry Ellison is close to acquiring the Warriors from the team's current owner, Chris Cohan, sources close to the negotiations said Tuesday night.

According to those sources, Ellison, CEO of Oracle Corp., outbid 24-Hour Fitness founder Mark Mastrov, among others. If the current deal is completed, Ellison would control 80 percent of the franchise, and incumbent minority owners Michael Marks, Jim Davidson, John Thompson and Fred Harman would retain their stakes.

Sources vary greatly on the final price tag, ranging from those who believe Ellison will pay close to his initial bid of $315 million to others who think the price tag will top the $401 million cost, the NBA record, of the Phoenix Suns in 2004. There are sources who believe the deal was completed late Tuesday night, and others who characterized the conclusion merely as "imminent."

Among the things sources agree upon is that Ellison submitted the winning bid and that, as a potential owner who was pre-approved by the league, his takeover shouldn't encounter obstacles after the deal is finalized.

A successful purchase of the Warriors would come as little surprise to those who have encountered Ellison in the Silicon Valley business arena over the years.

Ellison founded Oracle as a database company in 1977 and built it into the largest provider of business software in the world. Last month, Oracle reported fiscal 2010 earnings of $26.8 billion, up 15 percent over the previous year.

Oracle's growth has come in part from Ellison's rapacious appetite for acquisitions. He hasn't been shy about opening his wallet to buy personal toys - as well as competitors.

Starting in 2004, Oracle rattled off a series of high-profile acquisitions, including a $10.3 billion purchase of PeopleSoft, an $8.5 billion purchase of BEA Systems and, most recently, a $7.4 billion merger with Sun Microsystems.

Ellison has been criticized for being reckless and boastful - and sometimes difficult to work for - but his drive and vision have helped keep Oracle in a leadership position in a field commonly referred to as "enterprise," or business, technology.

That hasn't stopped Ellison from being an avid sportsman, most notably in the world of sailing. Earlier this year, his BMW Oracle team won the America's Cup in Valencia, Spain, bringing to a head Ellison's lengthy quest to conquer the sport.

No one knows exactly how Ellison will manage an NBA franchise, but fans appear ready to welcome any and all changes after 16 underwhelming seasons under Cohan. The much-maligned owner has watched as his franchise made one playoff appearance - fewer than any other NBA team in the time frame of his ownership - and posted a 477-803 record (.373), bettering only the Los Angeles Clippers during that period.

Cohan's tenure has been tainted by financial problems, locker-room turmoil and amplified fan unrest. In 2007, the Internal Revenue Service said Cohan owed more than $160 million in back income taxes and penalties from the 1998 sale of Sonic Communications.

Still, Cohan has shown the willingness to spend money on scouting and players, within the bounds of the league's luxury tax, and has been a regular at Oracle Arena. He was there in January, when - with Ellison sitting courtside for the Cleveland game - a fan held a sign reading, "Dear Larry Ellison, please buy this team. Thanks, the Warriors fans."

Fan unrest has been mirrored by team turmoil, which has been characterized by infighting among players, coaches and the front office. And there has been lots and lots of losing. Most recently, fans were frustrated when the Warriors didn't renew the contract of general manager Chris Mullin, were forced to trade Stephen Jackson and Jamal Crawford, and did little during the since-squashed drama between guards Monta Ellis and Stephen Curry.

Despite those problems, Cohan has enjoyed surprising fiscal success. Cohan purchased the team for $119 million in 1994, and Forbes now values the franchise at $315 million. The magazine also deemed the Warriors as one of 18 franchises in the 30-team NBA that made money last year, ranking 11th at $11.9 million.

In March, Cohan retained Galatioto Sports Partners to conduct the sale of the team and act as financial adviser during the process. Both the Warriors and their financial advisers declined public comment until a sale agreement is reached.